Reactive dyeing systems using dyes with carboxylic acid groups on polyvinyl alcohol

ABSTRACT

Carboxy substituted aromatic chromophores are reactively linked to fibers containing alcoholic hydroxyl groups, amino groups or thiol groups, such as cellulosic fibers, with the linkage produced in the presence of a cyanamide compound, such as cyanamide or dicyandiamide.

This is a continuation-in-part of application Ser. No. 772,738, filedFeb. 28, 1977 now U.S. Pat. No. 4,111,648 which in turn is acontinuation of Ser. No. 588,840 filed June 20, 1975 now abandoned.

BACKGROUND OF THE INVENTION

The present invention relates to dyeing of fibers and more particularlyto reactively dyed fibers in which a chromophore is chemically linked tosites on the fiber.

Dyes are retained in fibers by physical adsorption, salt ormetal-complex formation, solution, entrapment, or the formation ofcovalent chemical bonds. Physical adsorption and solution, in which thedye is partitioned between the fiber and the surrounding aqueous phase,are equilibrium processes, and only by very careful selection of thedyes used, can good washfastness properties be achieved. Salt and metalcomplex formation are also equilibrium reactions and, though generallythe retention of the dye is favored more than in physical adsorption,washfastness may still present a problem. The dyes that are held byentrapment (azoics, vats and sulfurs) are virtually insoluble in waterand show excellent fastness to washing, but have other disadvantages.They are, for example, difficult and expensive to apply; loose dye,which is not easily washed off, may be deposited on the surface,resulting in low fastness to rubbing (crockfastness), and the finalshade of the dyeing does not develop until completion of the wholedyeing cycle and aftertreatments.

Chemical bonding of dye to fiber for fixation of dye was recognized asearly as 1895. The reactive dye systems presently available require thatthe dyes contain a functional group capable of forming a covalentchemical bond with the fiber.

Fiber-reactive dyes are employed quite widely in coloring cellulosicsand proteinaceous fibers. They, of course, exhibit excellentwashfastness, resistance to rubbing, tinctorial powers, ease ofapplication and leveling. The latter quality is a measure of uniformityand most important for long dye runs and color matching. The reaction ofthe dye with cellulosic fibers is basically an etherification oresterification reaction and is broadly represented as: ##STR1##

    Dye-SO.sub.2 CH.sub.2 CH.sub.2 OH+Cell-OH→Dye-SO.sub.2 CH.sub.2 CH.sub.2 O-Cell                                           (II)

Reactive dyes of Type I are labile halides, and as such they are bynature of limited stability in storage and difficult to work with. Theirreactions are generally effected under alkaline conditions. There arefew presently available reactive dye systems which operate well underacidic conditions. An acidic system is often desirable in the dyeing ofmixed fabrics such as cotton blends with polyester, wool or nylon, thelatter two fibers being dyeable by acid dyes. However, acid dyesgenerally have no affinity for cellulose and usually only find use indyeing of proteinaceous fibers.

The American Cyanamid Company has published a booklet entitled"Cyanamide", which sets forth a considerable number of reactions ofcyanamide and dicyandiamide. Page 32 of this booklet indicates thatcyanamide was long known to be a dehydrating agent when warmed inanhydrous formic acid or when used in the esterification of lactic orsalicylic acid with absolute ethanol. Note Pratorius-Seidler, G.,J.prakt. Chem [2] 21, 129-50 (1880); C. 1880, 245. A number of papers haveinvestigated the reaction of cyanamide with carboxylic acids, and haveproposed a mechanism wherein the acid is converted to the anhydride byinteraction with cyanamide, with formation of urea. Subsequently theurea is acylated by the anhydride to produce a ureide, which at elevatedtemperatures interacts with the acid to produce an amide.

The use of cyanamide and phosphoric acid to impart flame retardantproperties to cotton and other cellulosic fabrics is well known to theart. For instance, O'Brien, "Cyanamide Based Durable Flame-RetardantFinish for Cotton", Textile Research Journal, March, 1968, pp. 256-266indicates, at page 265, that the reaction of cyanamide and phosphoricacid with cellulose results in a cross-linking of cellulose molecules.From the properties of the resulting product, it is suggested that thecross-linked cellulose is some type of dicellulose phosphate ester.

Copending, commonly assigned application Ser. No. 534,349, filed Dec.18, 1974, to Swidler and Sanderson, discloses the use of cyanamidecompounds, such as cyanamide and dicyandiamide, to aid in the reactivedyeing of substrates containing certain types of active hydrogen atoms,including cellulosic fibers, with phosphorus-containing dyes, such asdyes containing phosphonic acid groups, or salts thereof.

U.S. Pat. No. 3,535,308 discloses a process for preparing organic estersof polyhydroxylic polymers. These organic esters are indicated to havevarious uses, including application to textiles, as presented in moredetail in, for example, Ott et al, Cellulose and Cellulose Derivatives,Vol. V, Part II, pp. 763-820. The polymers are prepared by contacting apolyhydroxylic polymer containing esterifiable hydroxyl groups withcyanamide or cyanamide salts and a carboxylic acid for a time sufficientto impregnate the polymer with the cyanamide and the acid. Thereafterthe impregnated polymer is heated for a time sufficient to react thecomponents to produce the partially esterified polymer. The degree ofesterification is indicated to depend upon many different factors, andit is indicated that polymers containing as many as one ester groupingfor every 10-30 esterifiable hydroxyl groups have been prepared.

SUMMARY OF THE INVENTION

The present invention provides a method of dyeing a polymeric substratecontaining certain Zerewitinoff-active hydrogen atoms, such asnon-phenolic alcoholic hydroxyl groups, thiol groups, or amino groups.The substrate is contacted with a cyanamide compound, such as cyanamideor dicyandiamide, and with a carboxy-substituted aromatic dye. Thecyanamide and the dye carboxylic groups are present in a ratio ofequivalents of at least about 2:1 respectively, and in a system having apH of about 1.5 to about 11. The substrate contacted with the cyanamidecompound and the dyes is heated to a temperature of at least 200° F. fora time sufficient to fix the dye on the substrate.

The resulting dyed textile substrates exhibit reasonably good fixation,especially when the carboxyl group is attached to the dye through thecarbon atom of a phenyl ring, with the phenyl ring carrying an aminogroup on a carbon atom adjacent to that attached to the carboxyl group,such as in derivatives of anthranilic acid.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides a method of dyeing certain polymericsubstrates containing certain types of active hydrogen atoms, whereinthe substrate can be reactively dyed in acidic to mildly alkalinesolutions. It is believed that the dye system of the present inventionresults in reactively dyed substrates by chemically linking the dye tothe substrate through a carboxylic ester linkage, but this theory hasnot been finally confirmed. Following this theory, it appears that theester is formed by the following reaction: ##STR2## wherein ROH is, forinstance, a cellulosic polymer, and Dye is a chromophore carrying theauxochromic carboxy group.

The cyanamide compound appears to function as a condensation agent forthe reaction. The dye can be directly reacted with the substrate, oralternatively certain dyes can be formed in situ. For instance, sincemost azo dyes are produced by a simple coupling of the two dyeintermediates, the first intermediate, such as p-aminobenzoic acid, maybe reacted with the substrate by the method of the invention, afterwhich the thus derivatized substrate is diazotized and coupled with thesecond intermediate to produce the color.

The dye may be reacted with the entire substrate, either by directapplication or by in situ formation as above, or it may be applied inpatterns by any of several conventional printing techniques, usingeither the direct or the in situ approach. For example, p-aminobenzoicacid may be printed onto the substrate and reacted, diazotized, andcoupled as above. Unused coupling intermediate on the background areasmay afterwards be scoured away. As will be clear, the first intermediatemay be reacted overall with the substrate and the coupling intermediateapplied by printing, but this approach is generally less preferred.

In the dye system of the present invention, a single group, the carboxylgroup, serves both as an aqueous solubilizing group and as the potentialfiber reacting coupling site. The present reactive dyes can besynthesized easily, and in most instances they are less complex thanheretofore available reactive dyes. The dyes and their dyed products,both show superior resistance to water and other destructive agents.

The substrate contains reactive alcoholic groups, thiol groups, and/oramino groups. The substrates containing non-phenolic alcoholic groupsare particularly preferred, especially cellulosic substrates. Thereactive dyes may be applied to substrates containing alcoholic hydroxylgroups, especially cotton, and may be used to dye fibers, films, yarns,cords, threads, paper, non-woven fabrics, woven fabrics, knittedfabrics, pile fabrics, velvets, carded webs and webs formed on a randomwebber. The reactive sites on the substrate will have the formula --OH;--NH₂ (amino) or --SH. The process of the present invention results inthe fixation of reactive dyestuffs on rayon and fixation may be obtainedon wool, but the depth of shade is not as good as with rayon. Fixationis also obtained on nylon but the depth of shade is somewhat inferior tothat of wool. While the substrate may be in the form of cast or othermassive articles, it is greatly preferred that the substrate be atextile fabric or a textile yarn, filament or fiber, and most especiallyof an organic polymer containing alcoholic groups.

The cyanamide compound will be of the general formula ##STR3## whereinX¹ and X² are hydrogen, lower alkyl, or together are ##STR4## whereineach X³ is independently hydrogen or lower alkyl. Thus, methylcyanamide,dimethylcyanamide, ethylcyanamide, diethylcyanamide, butylcyanamide,dibutylcyanamide, and other cyanamide compounds falling within the scopeof the above formula disclosed in the foresaid American Cyanamid Company"Cyanamide" booklet, the disclosure of which is hereby incorporated byreference, may be used in place of cyanamide or dicyandiamide. However,cyanamide and dicyandiamide are particularly preferred, due to theirlower cost and ready availability. Compounds of the above generalformula may exist in tautomeric form and these tautomers are intended tobe included in the general formula.

The dyes that can be utilized in the process of the present inventioncan be of diverse type and structure, including anthraquinone,phthalocyanine, azo, benzanthrone, pyrazolone, naphthoquinone,triarylmethane and cyanine. The dye must contain at least one carboxylgroup, or salt thereof, to impart water solubility and to provide areactive site to attach to the reactive hydrogen atoms on the substrate.The dye may contain other aqueous solubilizing groups, such assulphonate groups, and may contain other substituents, as long as suchother substituents do not interfere with the aqueous solubilitycharacteristics or with the dye fixation reaction.

It is most preferred that the carboxyl group be directly attached to aring carbon atom of an aromatic ring of the dye. In a particularlypreferred embodiment, wherein especially good levels of fixation havebeen obtained, the carboxyl group is directly attached to such a ringcarbon atom, and the next adjoining ring carbon atom carries an amino(--NH₂) group. Thus, the dye will be of the general formula ##STR5##where R_(D) is the remaining part of a dye and is attached to oneposition of the aminocarboxyphenyl ring. Clearly the dye may contain oneor more, generally one or two, aminocarboxyphenyl rings.

Certain aminocarboxy ring-substituted anthraquinone dye intermediatesare known (see, e.g., Colour Index, Vol. 4, pages 4722-3) for theproduction of dyes.

Another aspect of the present invention resides in the provision of adyebath containing a tinctorial amount of, as one of the essentialcomponents therein, a dye of the general formula ##STR6## where R'_(D)is the remaining part of the dye and is attached through a single or, asin naphthalene or anthraquinone derivatives, two adjacent ring positionsof the aminocarboxyphenyl ring.

Alternatively, the carboxyl group may be attached to a ring carbon atomof an aromatic group in the dye by way of an alkylene bridging groupcontaining 1-3 carbon atoms, or an oxyalkylene bridging group containing1-3 carbon atoms, as illustrated in Example 11 hereinafter. Furthermore,the carboxyl group may be attached to a carbon atom of an aromatic groupin the dye through a group of the formula: ##STR7## wherein R' ishydrogen, alkyl of 1-3 carbon atoms, or another --C_(n) H_(2n) COOHgroup, and n is 1 to 3.

It will be readily appreciated by those in the art that salts,especially alkali metal salts and ammonium salts of the carboxylic acidradical, may be readily utilized.

The reactive dyeing process of the present invention involves theformation of an aqueous solution or partial suspension (wherein the dyeis not wholly dissolved) of a dye, or a dye precursor, containing atleast one chemically linked carboxyl group. The aqueous solution orpartial suspension will contain that amount of dye necessary to produceon the substrate a commercially acceptable coloration, and the solutionor partial suspension will generally contain at least 0.1 weight percentof the dye, and generally no more than 10 weight percent of the dye,depending upon the desired depth of said shade and the intensity of thedye. The dye concentration in the aqueous solution will more commonly bebetween 0.05 and 5% by weight, and the concentration of reacted dye onthe fabric is believed to be generally in the range of 0.01 to about 0.5weight percent, although much greater concentrations of dye on thefabric can be used, even up to 5.0 weight percent or more if desired. Itwill be appreciated by those in the art, however, that the above rangesare not always used, as the values in question may vary according to thedesired depth of shade, the strength or intensity of the dye, andsimilar factors.

The pH of the aqueous system is preferably controlled within the rangeof about 4-6, but can vary from about 1.5 to about 11.0. Lower values ofpH can be provided by the addition to the aqueous solution of 0.05-5weight percent of an acid which preferably will not volatilize at thecure temperature, and which does not cause undue degradation of thesubstrate, such as, for instance, phosphoric acid, lower alkylphosphonic acid and chloroacetic acid. In some instances, the additionof the acid appears to improve the efficiency of the dye immobilization,as greater fixation will be noted after the curing step. Normally, theamount of cyanamide compound in the aqueous solution will be increasedif the acid addition is used. Higher pH baths which may be utilizedgenerally contain salts which are converted to the acid form duringcure, such as ammonium salts of the carboxylic acid. Such higher pH dyebaths may be necessary in situations which may present corrosionproblems, or when using mixed fiber systems or fibers which would beadversely degraded at low pH.

In the dye bath the ratio of equivalents of cyanamide compound tocarboxyl acid function of the aromatic dye is at least about 2:1. Whilegreater excesses of the cyanamide compound may be used, such as anequivalents ratio of up to 100:1, generally no benefit will accruetherefrom. Normally, the ratio of equivalents of cyanamide compound tocarboxylic acid function will be in the range of about 2:1 to 15:1.

The curing of the reactive dye system is generally conducted attemperatures of at least 200° F. and normally below 450° F. The fabricmay optionally be preliminarily dried before the curing step. The curetime may vary from the order of seconds to hours, depending upon thecure temperature, the dye concentration and the substrate.

As mentioned previously, the cyanamide compound appears to function as awater soluble condensation agent which assists in the formation of anester linkage between the dye and the substrate. The cyanamide compoundis preferably cyanamide or dicyandiamide.

The dyebath may also contain minor amounts of conventional additives anddye assistants, including stabilizers, antimigrating agents, wettingagents, thickening agents and the like.

It will be readily appreciated that dyes containing carboxylic acidsubstituents that are known to the art may be used in the practice ofthe present invention. Some of these known dyes are direct dyes, andsome are mordant dyes. Suitable dyes are disclosed in the Colour Index3rd Edition, The Society of Dyers and Colourists, Bradford, Yorkshire,England, 1971 (and especially volume 4 thereof), the disclosure of whichis hereby incorporated by reference.

A new group of dyes, exemplified by Example 5 hereinafter, constitutesderivatives of mono or dichlorotriazinylamino dyes wherein all of thelabile chlorine atoms on the triazine ring have been replaced, byconventional means well known in the art, by non-labile groups, at leastone of which contains a carboxylic acid group.

The wide range of variations in chromophores and the partialsubstitution of halide groups in conventional reactive triazine dyes isdiscussed in detail in W. F. Beech, Fibre-Reactive Dyes, Logos Press,Ltd., London, 1970, pages 114-131, the disclosure of which is herebyincorporated by reference. The idea of the present invention is theapplication of the known techniques of partial replacement of thereactive halides to their total replacement, thereby eliminating thestorage stability and other problems inherent in chlorotriazine dyeswhile retaining their capacity for covalent bonding with cellulose.

This group of the new modified dyes of the invention have the generalformula: ##STR8## wherein R_(D) " is the remaining part of a dye, thelinkage of which to the triazine ring is preferably through an ##STR9##group, wherein R" is H or CH₃, R is H or CH₃, X is ArCOOH wherein Ar isphenyl or naphthyl, which may be further ring-substituted by lower alkylof 1 to 4 carbon atoms, Cl, Br, NO₂, SO₃ H, and COOH, Y is X, H, CH₃, orphenyl, which may be substituted by lower alkyl of 1 to 4 carbon atoms,Cl, Br, NO₂, and SO₃ H.

It is obvious that when Y is an inert group, the resulting dye, unlessthere be carboxylic groups within the chromophore, performs as amonobasic carboxylic acid in the process of the present invention. WhereY is a second X group, the dye exhibits the bonding performance andother advantages of a dye with two reactive carboxylic acid groups.

Carboxylic group reactivity may be enhanced not only by the presence ofone or two arylcarboxylic groups on the triazine ring as shown in theforegoing formula, but also by the presence of carboxylic groups in thechromophore.

One familiar with the technology of reactive dyes will readily realizethat the concept here presented is adaptable not only to triazinereactive dyes, but to related cyclic dyes derived from pyridazines,pyridazones, pyrimidines, and the like.

The modified triazine and the like dyes may be conveniently made fromcommercially available reactive dyes by replacement of their activehalogens. It is obvious, however, that they may also be made byalternative routes, not necessarily passing through the conventionaldyes, from intermediates normally used in making the conventionalchlorotriazine and the like dyes.

The process of the present invention may be conducted in commerciallyavailable machinery used for dyeing textiles or printing textiles,including both continuous and non-continuous process apparatus. Thesubstrate, especially when in the form of fabric or sheet material, maybe impregnated with the dye solution and then subjected to curing byheating in the indicated temperature range in, for example, a hot fluedryer, an oven or a stenter. The substrate impregnation may be conductedby padding the substrate with an aqueous solution containing the dye andthe cyanamide compound. The process of the present invention may also beconducted by conventional textile printing methods, for instance, bylocally printing a textile substrate with a solution containing the dyeand the cyanamide compound, and thereafter subjecting the printedsubstrate to an elevated curing temperature. Also, a carboxylicacid-substituted dye precursor may be reacted with the substrate by theprocess of the present invention, and thereafter coupled through an azolinkage to the other half of an azo dye.

The present invention provides a novel acid system for the fast dyeingof fibers containing alcoholic hydroxyl, thiol or amino groups, with thereactively dyed fibers exhibiting good color and stability to hot basicmedia.

The dye, the substrate, and the cyanamide compound may be broughttogether in any particular order, although as indicated hereinabove, thedye and the cyanamide compound together with any desired conventionaladditives or assistants will normally be in the form of an aqueoussolution or partial suspension, which is padded or otherwise applied tothe substrate. At least a coloring amount of the dye will be reactedwith the substrate.

Mixtures of types of substrates, mixtures of dyes and/or mixtures ofcyanamide compounds may be used if desired.

A number of modifications of the present process can be utilized. Asdiscussed previously, the dye may be formed on the substrate in situ, byreacting a carboxyl-substituted compound with the substrate andthereafter coupling the resulting compound to form an azo dye, or otherchromophore. Alternatively, the aromatic dye containing at least onecarboxylic acid substituent can be applied to a textile fabric byconventional methods, and then the so-treated textile fabric may besubjected to an after-treatment with the cyanamide compound.

In some instances, dyes containing two carboxylic acid groups will befound to exhibit greater efficiency of fixation, when used in theprocess of the present invention, and affixed to cotton or othersuitable substrate.

The process of the present invention equals or excels other dyeingsystems now in use for the continuous dyeing of cotton. The presentprocess conveniently utilizes a pad, pre-dry, bake, rinse, dry systemwhich can be conducted on existing plant equipment. Most reactive dyeingsystems are based on using an alkaline dye environment, whereas theprocess of the present invention operates extremely well on the acidside with a pH of, for example, about 5, and thus is more compatiblewith the disperse dyes used in the thermosol dyeing of polyester/cottonfabrics. Dye migration problems can be controlled by normal adjustmentsin the padding and pre-drying steps, and such adjustments are quiteeasily made on polyester/cotton fabrics. The dyes produced by thepresent process are quite consistently level. The strength loss of thecotton fabric is generally under 5%, which is about normal for reactivedyeing processes. Color loss resistance is excellent, with the resultsfrom 10-25 washes looking very favorable. The light fastness of the dyedfabrics of the present invention is at least competitive with otherreactive dyes based on similar chromophores, as is also true of othercharacteristics, such as resistance to dry cleaning.

Another major advantage of the dye system of the present invention isthat the dyes are not subject to hydrolysis during storage, in distinctcontrast to the reactive dyes which are now on the market, which have arestricted shelf life. The dyes of the present invention should lastindefinitely under storage conditions, and this is basically becausethey are stable to moisture attack, as compared to the commerciallyavailable reactive dyes.

In other words, the dyes of the present invention are, in their originalunreacted state, chemically unaffected by moisture or water. Thus, theywill last with full efficiency for years, which is in distinct contrastto reactive dyes designed for alkaline-side dyeings.

Another advantage of some of the dye systems of the present invention isthe level of fixation of the dye on the fiber which can be obtained.

A preferred class of carboxy-substituted aromatic dyes are of theformula ##STR10## wherein X is --COOH, --C_(n) H_(2n) COOH, OC_(n)H_(2n) COOH or ##STR11## R' is hydrogen, alkyl of 1 to 6 carbon atoms,or --C_(n) H_(2n) COOH, n is 1 to 3, and R_(D) is the remaining part ofa dye and may be singly or doubly (as in a naphthalene derivative)attached to phenyl ring A, which may contain other substituents, such asamino, alkyl, hydroxyl, alkoxy, and the like.

EXAMPLES OF THE INVENTION EXAMPLE 1

200 ml of an aqueous solution containing the following ingredients:

2 gm. CI Mordant Yellow 8 (CI 18821) of the formula ##STR12## 16 gm.cyanamide (50% aqueous solution) 6 gm. H₃ PO₄ (85% aqueous solution)

0.5 gm. Igepal CO-710 (nonylphenoxypolyethyleneoxy)ethanol surfactant

was prepared and padded on 100% cotton fabric at a pad pressure of 15psi. The padded fabric was dried at 220° F. for 2 minutes, and thencured at 390° F. for 45 seconds.

Rinsing the dyed fabric in hot water containing a small amount ofnonionic detergent produced only slight washdown.

EXAMPLE 2

A 600 ml exhaust dyebath containing 1.0% owf (0.2 g.) of Direct Orange73 (CI 25200) of the formula: ##STR13## and 0.6 ml of Calsolene Oil, asulfated ester wetting and penetrating agent sold by ICI America, Inc.,was heated to 120° F. 20 grams of 100% cotton fabric was added, and thetemperature was slowly raised to 200° F. Sodium chloride (10 g) wasadded in portions over a period of one hour, while maintaining the bathat 200° F. The bath was then dropped and the fabric was given a coldwater rinse, followed by a cold rinse with 5 grams of salt in 600 mlwater.

The fabric, after drying, was post-treated with an aqueous solutioncontaining 3 volume % phosphoric acid (85% aqueous solution), 8 volume %cyanamide (50% aqueous solution), 0.5% Igepal CO-710 surfactant, and 3.0volume % glycol diacetate. The post-treatment solution was applied bypadding at 10 psi, and then the padded fabric was dried at 220° F. forone minute and cured at 390° F. for one minute. Samples of thepost-treated fabric, and samples of the dyed fabrics which had not beensubjected to the post-treatment, were subjected to 10 home launderings.After 10 machine washes, the ratings on the standard gray scale for theuntreated fabric was 2.5 and for the treated fabric was 4.5.

EXAMPLE 3

Two aqueous solutions were prepared, containing the followingingredients:

A. 8 wt. % cyanamide (50% aqueous solution) 3 wt. % (NH₄)₂ SO₄

B. 3 wt. % 3-methyl-6-nitrobenzoic acid 3 wt. % Diethylene glycoldiacetate

Solution A was padded on 100% cotton at a pad pressure of 20 psi, andthe padded fabric was dried at 200° F. for one minute. Solution B wasthen padded on the fabric, over solution A, at a pad pressure of 20 psi,subjected to a similar drying step, and then cured at 380° F. for oneminute. The nitro group was then reduced to the amine by heating for 10minutes at 160° F. in an aqueous solution containing 3 grams per literof 50% NaOH and 3 grams per liter sodium hydrosulfite. The amine wasthen diazotized by treating the fabric in a bath containing 3 g/liter ofsodium nitrite and 3 g/l conc. HCl at a temperature of 35°-40° F. for 40minutes and thereafter coupled with β-naphthol by removing the fabricfrom the diazotizing solution and immersing it in a solution of 1 g/lβ-naphthol dissolved with 1 g/l 50% NaOH and 2 ml of methanol, at atemperature of 35°-40° F. The fabric exhibited an orange color, whichhad reasonably good color retention.

EXAMPLE 4

An aqueous bath containing 0.5% C.I. Direct Brown 154 (CI 30120) of theformula: ##STR14## was padded onto a 100% cotton fabric, and the paddedfabric was steamed for 45 seconds. The steamed fabric was thenpost-treated with an aqueous bath containing the following ingredients:

3 wt. % H₃ PO₄ (85%)

8 wt. % cyanamide (50%)

0.5 wt. % Igepal CO-710

A post-treatment bath was applied by padding onto the fabric at a padpressure of 15 psi. The padded fabric was dried at 200° F. for oneminute and cured at 240° F. for one minute. Retention of the colorduring washing was good.

EXAMPLE 5

The dye of the formula ##STR15## was prepared by reacting CI ReactiveRed 4 (CI18105) with p-aminobenzoic acid. 5 g. commercial Reactive Red 4(approximately 50% active dye) was dissolved in 100 ml. water. Asolution of 1 g. p-aminobenzoic acid and 0.2 g. NaOH in 50 ml. water wasthen stirred into the dye solution. The pH was adjusted to 6.8 with HCland the mixture warmed at 100°-120° F. for 12-14 hours. The volume wasthen adjusted to 150 ml. to give an approximately 2 percentconcentration of the desired dye.

An aqueous dyebath was prepared containing 1% of the dye, together withthe following ingredients (based on volume):

3% H₃ PO₄ (85% aqueous solution)

8% cyanamide (50% aqueous solution)

0.25% Igepal CO-710

The above solution was padded onto 100% cotton at 15 psi, dried at 220°F. for one minute and cured at 300° F. for two minutes. Rinsing in hotwater containing a small amount of nonionic detergent removed only asmall amount of the dye.

EXAMPLE 6

200 ml of an aqueous solution containing the following ingredients:

2 g. 3,5-diaminobenzoic acid

0.5 g. H₃ PO₄ (85% aqueous solution)

16 g. cyanamide (50% aqueous solution)

1 g. Igepal CO-710

was prepared and padded onto 100% cotton fabric at a pad pressure of 15psi. Two samples were each dried at 220° F. for two minutes, and one ofthe samples was then cured at 390° F. for one minute. Each sample wasthen thoroughly rinsed to remove any unreacted diaminobenzoic acid anddried at 220° F. for one minute. The diaminobenzoic acid moiety on thefabrics was then diazotized and thereafter coupled with β-naphthol, asin Example 3. An organe color developed on the cured sample, which colorcould not be extracted when treated with hot dimethylacetamide (270° F.)for 2 minutes. The sample which was not cured did not develop any colorwhen diazotized and coupled with β-naphthol.

EXAMPLE 7

An aqueous dye solution was prepared from the following ingredients:

0.5 wt. % Rhodamine B (CI Basic Violet 10, CI 45170) of the formula:##STR16## 3% by volume 85% H₃ PO₄ 10% by weight Urea

8% by volume cyanamide (50% aqueous solution)

This solution was then padded on 100% cotton fabric at a pad pressure of15 psi, dried for 2 minutes at 200° F. and then cured for 45 seconds at390° F. A swatch of the treated fabric was rinsed in hot watercontaining a small amount of nonionic detergent, and very littlewash-off occurred.

EXAMPLE 8

CI Direct Brown 154 (CI 30120) was exhausted onto 100% cotton fabric bythe method of Example 2. The dyed fabric was then aftertreated with abath containing the following ingredients (based on volume):

3% H₃ PO₄ (85% aqueous solution)

8% cyanamide (50% aqueous solution)

3% glycol diacetate

0.25% Igepal CO-710

The aftertreatment bath was applied by padding at a pad pressure of 15psi. Two fabric samples were padded and then dried at 220° F. for oneminute, and one of the samples was then cured at 390° F. for 45 seconds.Both the dried-only sample and the cured sample, together with a control(dyed but not aftertreated) were then washed 10 times. The control had a2 rating on the gray scale whereas both treated samples had ratings of3.5. The results indicate that further curing after drying was notnecessary with this dye.

EXAMPLE 9

Example 8 was repeated, except the dye was CI Direct Yellow 44 (CI29000) of the average formula: ##STR17## After 10 machine washings, therating of the control on the gray scale was 3, while the treated, curedsample rated 4.5.

EXAMPLE 10

Example 8 was repeated, except the dyestuff was CI Direct Green 26 (CI34045) of the formula: ##STR18## A satisfactory dyeing resulted.

EXAMPLE 11

Example 8 was repeated, except the dye was CI Direct Blue 158 (CI 24555)of the formula: ##STR19## After 10 machine washings, the ratings on thegray scale for the control was 3.0, whereas the treated sample rated4.0.

EXAMPLE 12

Example 6 was repeated, except the phosphoric acid was replaced by anequivalent amount of concentrated hydrochloric acid. The resultsobtained were similar.

EXAMPLE 13

0.5 grams of CI Direct Green 26 (CI 34045) was dissolved in 100 ml ofwater. Then 1 gram of Igepal CO-710, 1 gram of H₃ PO₄ (85% aqueoussolution) and 16 grams of cyanamide (50% aqueous solution) were added tothe dye solution. The resulting solution was then brought to a totalvolume of 200 ml by the addition of water, and the pH adjusted to 7 withammonium hydroxide. The resulting solution was padded onto 100% cottonfabric at a pad pressure of 15 psi, dried 2 minutes at 220° F., andcured 45 seconds at 390° F. The padded swatch was then rinsed in hot andin warm water containing a small amount of nonionic detergent to removeany unfixed dye. Only a very small amount of color washed off.

EXAMPLE 14

Example 13 was repeated, replacing the dye with a red dye of thestructure: ##STR20## This dye, and others hereinafter, were made fromthe appropriate amines and coupling agents by the conventionaldiazotization and coupling procedures detailed in Fierz-David andBlangey, Fundamental Processes of Dye Chemistry, IntersciencePublishers, 1949, pp. 239-59. On rinsing the sample, greater than 85% ofthe dye was retained on the fabric.

The synthesis of this dye was as follows:

7.1 g (0.05 mole) 2-hydroxy-4-aminobenzoic acid was dispersed in waterand to this was added 25 ml cold hydrochloric acid solution (37%) whilestirring to form a fine dispersion. To this solution was added 3.7 g.NaNO₂ (0.05 mole) dissolved in 20 ml water. The solution was stirred for30-45 min. for complete diazotization to occur.

The solution containing the diazonium salt was added to a solutioncontaining 16.8 g. (0.05 mole) of N-acetyl "H" acid and 15 g. 50% NaOHin 100 ml water at 5° C. The solution was maintained at a temperature of5° C. while stirring for 30-45 min. A bright red color was formed. Thered dye was salted out, filtered and purified. The dye was then ionexchanged to form the free acid.

EXAMPLE 15

Example 13 was repeated, but the dye was replaced with the red dye ofthe formula: ##STR21## The dye was made by the following procedure: 6.8g. (0.05 mole) p-aminobenzoic acid was dispersed in 75 ml water andneutralized with 10.6 g (0.1 mole) sodium carbonate and cooled to15°-20° C. 3.7 g. NaNO₂ (0.05 mole) dissolved in 20 ml water was addedto the neutralized acid. The above mixture was poured carefully into amixture of 25 ml conc. HCl (37%) and 50 g. of ice with stirring. Theresultant mixture was stirred for 20-30 min. at a temperature of 5°-10°C. 4 g. of sulfamic acid was added to destroy excess nitrite.

The diazonium solution was added to a solution containing 16.75 g. (0.05mole) N-acetyl "H" acid and 10 g. sodium acetate and coupling and dyeisolation were accomplished as in Example 14. Upon rinsing of the dyedswatch, approximately 50% of the dye was retained.

EXAMPLE 16

The salted-out dye of Example 15 was converted to the ammonium salt, bypassing an aqueous solution of the dye through an ion exchange columnwith the exchange resin in the ammonium form. The resulting dye was thenused to replace the dye of Example 13, the procedure of which wasrepeated. When the resulting dyed fabric was rinsed, greater than 70% ofthe dye was retained on the fabric.

EXAMPLE 17

Example 13 was repeated, except the dye was replaced by the yellow dyeof the formula: ##STR22##

The dye was made by dispersing 3.2 g (0.025 mole) p-aminobenzoic acid in35 ml water and neutralizing with 5.3 g. (0.05 mole) Na₂ CO₃ and coolingto 15°-20° C. To this was added 1.9 g. (0.025 mole) NaNO₂ dissolved in10 ml. water. The solution was added to a mixture containing 15 ml.conc. HCl (37%) in 25 g. ice. The resultant solution was stirred for20-30 min. at 5° C.

The diazonium solution was added slowly to a solution containing 7.1 g.(0.025 mole) 1-(4'-nitrophenyl)-3-carboxy-5-pyrazolone and 15 g. Na₂ CO₃with stirring while maintaining the temperature at about 5° C. Themixture was stirred for 30-45 min. more and the yellow dye wasprecipitated with 10 ml. conc. HCl, filtered and dried. When the dyedswatch was rinsed, approximately 50% of the dye was retained on thefabric.

EXAMPLE 18

Example 13 was repeated, but replacing the dye with the red dye of theformula: ##STR23## The dye was made by the procedure of Example 15, butwith the p-aminobenzoic acid replaced with 0.05 mole2-chloro-5-aminobenzoic acid. Approximately 30% of the dye was retainedfollowing rinsing of the dyed sample.

EXAMPLE 19

Example 13 was repeated, replacing the Direct Green 26 with CI DirectOrange 8 (CI 22130) of the formula: ##STR24## Very little washoffoccurred on rinsing the dyed fabric.

EXAMPLE 20

Example 13 was repeated, but replacing the Direct Green 26 with CIDirect Yellow 44 (CI 29000) of the average formula: ##STR25## Little orno washoff occurred in the rinsing of the dyed fabric.

EXAMPLE 21

Example 13 was repeated, but using the reddish-brown dye of the formula:##STR26## in place of the Direct Green 26. The dye was made by theprocedure of Example 14, but with 8.1 g. (0.05 mole)2-chloro-4-nitroaniline as the diazotized amine and 12.6 g. (0.05 mole)m-toluidine-N,N-dipropionic acid as the coupling agent. Approximately30% of the dye was retained on the fabric following rinsing of the dyedfabric.

EXAMPLE 22

Example 14 was repeated, except the solution was padded onto amultifiber fabric instead of a cotton fabric. Fixation occurred oncotton, rayon, nylon and silk.

EXAMPLE 23

An aqueous dye bath was prepared, containing the following ingredients:

0.25 wt. % of CI Mordant Yellow 14 (CI 14055) of the structure:##STR27## 0.5 wt. % H₃ PO₄ (85% aqueous solution) 2.0 wt. %dicyandiamide

0.5 wt. % Igepal CO-710

The above dye bath was mixed and padded onto 100% cotton fabric, and thetreated fabric was dried at 220° F. and cured for 45 seconds at 390° F.The sample was rinsed and dried, and some fixation was found to haveoccurred, though inferior to the same treatment with cyanamide in placeof the dicyandiamide.

EXAMPLE 24

Example 13 was repeated, except the Direct Green 26 was replaced by CIDirect Green 8 (CI 30315) having the structure: ##STR28## Somewhatsimilar results were obtained.

EXAMPLE 25

Example 1 was repeated, except the Mordant Yellow 8 was replaced byMordant Yellow 14, having the structure: ##STR29## Similar results wereobtained to Example 1.

EXAMPLE 26

Example 1 was repeated, except the Mordant Yellow 8 was replaced by CIMordant Green 13 (CI 42005), having the structure: ##STR30## Somewhatsimilar results were obtained, as compared to Example 1.

EXAMPLE 27

Example 1 was repeated, except the Mordant Yellow 8 dye was replaced byCI Mordant Green 23 (CI 42010), having the structure: ##STR31## Resultsobtained were similar to those of Example 1.

EXAMPLE 28

Example 1 was repeated, except that Mordant Yellow 8 dye was replaced byCI Mordant Blue 52 (CI 42015), having the structure ##STR32## Resultsobtained were similar to those of Example 1.

EXAMPLES 29-36

These examples relate to the use of the following compounds:

p-aminobenzoic acid

4-nitrophthalic acid

3,5-diaminobenzoic acid

o-nitrophenylpyruvic acid

3-nitro-1,9-naphthalic acid

o-aminobenzoic acid

4-nitro-2-aminobenzoic acid

p-hydroxybenzoic acid

The compounds were diazotized and coupled after fixation on the cloth inorder to form the chromophores in situ.

Each of the above compounds was mixed into an aqueous solutioncontaining 8 volume % cyanamide (50% aqueous solution), 0.5 volume % of85% phosphoric acid, and 1.0 wt. % of the compound. The aqueous solutionwas then padded onto 100% cotton fabric, at a pickup of about 70-80%,dried and then cured for 45 seconds at 340° F. Where necessary, the pHwas adjusted by the addition of ammonium hydroxide in order to renderthe compounds soluble in the aqueous solution.

For those compounds having a nitro rather than an amino group, the nitrogroup was reduced to an amine by the procedure of Example 3. Thecompounds were then diazotized and coupled with either β-naphthol or4-amino-1-naphthalene sulfonic acid, as in Example 3, in order to formthe dye.

The cloth treated with p-aminobenzoic acid was given 5 and 10 machinewashings prior to and subsequent to coupling with β-naphthol, and theendurance in both cases was in the order of 80-90%.

For comparative purposes, p-aminobenzoic acid was compared withm-aminobenzenephosphonic acid in reactions on cotton, using cyanamide asthe condensation agent, followed by coupling with β-naphthol. Greatercolor yields and brighter shades of color were obtained with theaminobenzoic than with the aminobenzenephosphonic acid.

The free acids or the ammonium salts of the above compounds generallyundergo further fixation than their sodium salts.

While other acids, such as hydrochloric acid or sulfamic acid, workedwith p-aminobenzoic acid, it is preferred to use phosphoric acid, assomewhat better results were obtained.

Other carboxyl-containing dyes, which could be used in the aboveexamples with somewhat similar results, include those having thefollowing structure: ##STR33## As mentioned hereinabove, it has beenfound that reactive dyes having the following group: ##STR34## are moreeffective than similar compounds without the amino group, for couplingto cellulose. The dye will be of the formula ##STR35## wherein R'_(D) isthe remaining part of a dye and may be singly or doubly (as in anaphthalene derivative) attached to the aminocarboxyphenyl ring. This isillustrated by the following working examples:

EXAMPLE 37

An aqueous dye solution was prepared from a dye having the formula:##STR36## The dye was made as follows: 8.65 g. (0.05 mole) sulfanilicacid was dissolved in 25 cc 2 N Na₂ CO₃ solution and diluted with anadditional 25 cc water. To this solution was added 50 cc 1 N NaNO₂ andthe total solution was then added to 62.5 cc 2 N HCl in 50 g. ice. ThepH was adjusted to 3 with HCl and the mixture was stirred at 5°-10° C.for 20 minutes. The diazonium solution is then added slowly to asolution containing 5 g. o-aminobenzoic acid and 5.3 g Na₂ CO₃. Theyellow dye formed was precipitated with HCl. The dye bath contained 1.0%by weight of the above dye, 8% by volume of cyanamide (50% aqueoussolution), 0.5 volume % of 85% H₃ PO₄ and 0.25 volume percent IgepalCO-710. The dye solution was padded onto 100% cotton fabric to a pickupof 60-70 weight percent, dried at 220° F. and then cured for 90 secondsat 390° F. Washing with a nonionic detergent solution containing Na₂ CO₃resulted in a retention value of 33% of the dye on the fabric.

EXAMPLE 38

Example 37 was repeated, except the dye was replaced by the dye of thefollowing formula: ##STR37## The dye was made as follows: 7.1 g (0.025mole) 1-(m-aminophenyl)-3-carboxy-5-pyrazolone was dispersed in 50 mlwater, neutralized with 5.3 g (0.05 mole) Na₂ CO₃, and cooled to 15°-20°C. 1.9 g NaNO₂ (0.025 mole) dissolved in 10 ml water was then added.This solution was then poured slowly into a mixture of 13 ml conc. HCl(37%) and 40 g ice forming a fine dispersion. This fine dispersion wasthen added slowly to a solution containing 3.2 g (0.025 mole)o-aminobenzoic acid and 5 g. Na₂ CO₃, and when the reaction was completethe brownish-yellow dye was precipitated with conc. HCl, filtered anddried. The retention value was 58%.

EXAMPLE 39

Example 37 was repeated, but this time the dye was replaced by thebrownish-yellow dye of the formula: ##STR38## The procedure of Example38 was followed in making the dye, except that the diazonium solutionwas made from 4-amino-3'-carboxy-4'-hydroxyazobenzene. This exampleresulted in a retention value of 85%.

EXAMPLE 40

A mixture of 7.5 g (0.025 mole) bromaminic acid, 3.8 g (0.025 mole)3,5-diaminobenzoic acid, 1 g cuprous chloride, and 175 ml water wasstirred into a good dispersion in a flask equipped with a stirrer andcondenser. 50 ml ethanol and 13.5 g Na₂ CO₃ were added in portions at45°-50° C. over 35-40 minutes, after which this temperature wasmaintained for 18 hours. The resulting anthraquinone dye wasprecipitated by pouring the mixture into 50 ml 37% HCl andrecrystallized from 7% HCl. It had the formula ##STR39## This dye wasused in a bath containing 0.5% dye

0.5% H₃ PO₄ (85%)

0.5% igepal CO-710

4.0% cyanamide

The pH was adjusted to 5 and the bath padded on cotton fabric at 20 psi.The fabric was dried 2 minutes at 220° F., cured for 90 seconds at 390°F., and scoured with 0.5 g/l Na₂ CO₃ at 180° F. for 5 minutes. The colorretention was 40%.

EXAMPLE 41

This experiment used fiberglass cloth sized with polyvinyl alcohol asthe substrate. A dye of the following formula was used: ##STR40## A. Asa control an aqueous solution containing 0.5% of the above dye wasprepared and padded on a swatch of fiberglass cloth sized with polyvinylalcohol then dried and cured for 90 seconds at 215° C. (420° F.). Nocyanamide compound was used.

B. next an aqueous solution was prepared containing the followingingredients expressed in weight percent:

0.5% of the above dye

4.0% dicyandiamide

0.1% Igepal Co-710 (surfactant)

0.4% H₃ PO₄

0.2% ucar z-212

the above dyebath was adjusted to a pH of 5.5 and padded onto a swatchof PVA-sized fiberglass, dried and cured for 90 seconds at 215° C. (420°F.) in the manner of the previous examples.

Both swatches were scoured with a detergent solution of 1.5 g/lSynthrapol SP and 1.5 g/l soda ash at the boil for 2 minutes. Colorretention was then determined by measurement with a spectrophotometer.The results were as follows:

    ______________________________________                                                           retention (%)                                              ______________________________________                                        swatch A (control)    7.8                                                     swatch B             55.0                                                     ______________________________________                                    

These studies indicate that in the presence of the cyanamide compoundthe carboxylic dye reacts with the PVA on the fiberglass; there was noaffinity for the PVA in the absence of the cyanamide-containing paddingsolution.

Ucar Z-212, a nonionic thickener made by Union Carbide Corp., isreported to be a mixture of 70% hydroxyethyl cellulose, molecular weightup to 10,000 and 30% polyethylene glycol, molecular weight 4000. IgepalCO-710 is nonylphenoxypoly(ethyleneoxy)ethanol surfactant. SynthrapolSP, sold by ICI America, Inc., used as a detergent and wetting agent, isa blend of nonionic and ionic surfactants.

The term "retention" as used herein means that percentage of the colorremaining after one process rinse, the color of the fabric coming fromthe curing oven being taken as the base, i.e. 100%. The term "endurance"means the percentage of the base color remaining after the process rinseand five launderings, except where the number of launderings is noted tobe otherwise. The color measurements are made on a Beckman DBGspectrophotometer.

What is claimed:
 1. A method of forming a reactively dyed polymericsubstrate, said method comprising(a) contacting a polyvinyl alcoholsubstrate at a pH of about 1.5 to about 11 with(i) a cyanamide compoundselected from the group consisting of cyanamide, alkyl-substitutedcyanamide, dicyandiamide and alkyl-substituted dicyandiamide, whereinsaid alkyl groups each contain from 1 to 6 carbon atoms, and with (ii) acoloring amount of an aromatic dye of the formula Dye-COOH, wherein Dyeis an aromatic chromophore wherein the ratio of equivalents of saidcyanamide compound to each carboxylic acid function of said aromatic dyeis at least about 2:1, and (b) heating the contacted substrate to atemperature of at least 200° F. for a time sufficient to fix saidchromophore to said substrate by condensation reaction between saidactive hydrogen and the --COOH group of said dye so as to join thechromophore to the substrate through the C atom of said --COOH group. 2.A composition for reactively dyeing textile substrates containingnon-phenolic alcoholic substituents, said composition comprising anaqueous solution having a pH of from about 1.5 to about 11 andcontaining(a) at least 0.1% by weight of an aromatic dyestuff which issubstituted by at least one carboxyl acid group which is reactive withactive hydrogen atoms of said substituents so that the dyestuff can bejoined to the substrate through the C atom of said --COOH group, and (b)a water soluble cyanamide compound selected from the group consisting ofcyanamide, alkyl-substituted cyanamide, dicyandiamide andalkyl-substituted dicyandiamide, wherein the alkyl substituents containfrom 1-6 carbon atoms, wherein the ratio equivalent of cyanamidecompound to carboxylic acid is at least about 2:1.
 3. Compositionaccording to claim 2 wherein said dye has the formula ##STR41## whereinR'_(D) is the remaining part of a dye and is singly or doubly attachedto the aminocarboxyphenyl ring.
 4. A method of forming a reactively dyedpolymeric substrate, said method comprising(a) contacting a polymericsubstrate containing non-phenolic alcoholic active hydrogen atoms at apH of about 1.5 to about 11 with(i) a cyanamide compound selected fromthe group consisting of cyanamide, alkyl-substituted cyanamide,dicyandiamide and alkyl-substituted dicyandiamide, wherein said alkylgroups each contain from 1 to 6 carbon atoms, and with (ii) a coloringamount of an aromatic dye of the formula Dye-COOH, wherein Dye is anaromatic chromophore wherein the ratio of equivalents of said cyanamidecompound to each carboxylic acid function of said aromatic dye is atleast about 2:1, and (b) heating the contacted substrate to atemperature of at least 200° F. for a time sufficient to fix saidchromophore to said substrate by condensation reaction between saidactive hydrogen and the --COOH group of said dye so as to join thechromophore to the substrate through the C atom of said --COOH group. 5.Method according to claim 4, wherein said chromophore is an azochromophore.
 6. Method according to claim 4, wherein said chromophore isan anthraquinone chromophore.
 7. Method according to claims 4, 5 or 6,wherein said chromophore is substituted with a plurality of carboxylicacid substituents.
 8. Method according to claim 7, wherein saidchromophore contains two carboxylic acid substituents.
 9. Methodaccording to claim 4, wherein said carboxylic group is directly attachedto a ring carbon atom of a phenyl group, and an amino group is attachedto an adjacent carbon atom of the phenyl ring.
 10. Method according toclaim 4, wherein the contacted substrate of step (a) is dried prior toheating in step (b).
 11. Method according to claim 4, wherein saidsubstrate is a textile substrate.
 12. Method according to claim 4,wherein said textile substrate is an organic polymer containing aplurality of hydroxyl groups.
 13. Method according to claim 4, whereinsaid polymer is polyvinyl alcohol.
 14. Method according to claim 4,wherein said cyanamide compound is cyanamide.
 15. Method according toclaim 4, wherein said cyanamide compound is dicyandiamide.
 16. Methodaccording to claim 4, wherein said substrate is in fibrous form coatedwith polyvinyl alcohol.
 17. Method according to claim 4, wherein thechromophore is selected from the group consisting of anthraquinone,phthalocyanine, azo, benzanthrone, naphthoquinone, triarylmethane andcyanine chromophores.